The present invention relates to a mobile electronic device, such as a mobile telephone or personal organizer or computer, etc., of the type mentioned in the preamble of the independent claims.
Many mobile electronic devices have a hinged front panel, henceforth called a flip, which can be opened when the device is used for certain functions and which can be closed in order to reduce the bulk of the device when these functions are not required. One example of such a device is the mobile telephone known from the patent GB-A 2 297 661 which has a flip which can be folded down to expose a touch screen display. When the flip is folded up against the touch screen display the screen can be operated by means of a keypad consisting of a plurality of buttons which extend through the flip and which can be pressed by a user into contact with the touch sensitive parts of the touch screen display. There is no electrical connection between these buttons on the flip and the main unit. There is a flip position indicating switch in the main body of the unit which can be operated by a switch activation device disposed in the flip. The flip position indicating switch and switch activation device co-operate to produce a mode change signal which is sent to the processor of the mobile phone and which indicates if the flip is open or closed. If the flip is closed a first set of functions is available to the user and if the flip is open a second set of functions is available to the user. Mobile telephones of this type can be switched on and off by a hardware switch which disconnects the processor from the logic voltage supply in order to minimize unnecessary battery drainage caused by the logic voltage supply leakage current. It is not possible to use the flip position indicating switch in the main body of the unit which is actuated by the switch activation device in the flip to, for example, disconnect the processor from its logic voltage supply as the telephone is intended to be used for certain functions even when the flip is closed. It is not possible to use software to switch on the processor as the processor is completely switched off and hence cannot run any software when it is disconnected from its power supply. Thus a separate hardware switch is required which increases the manufacturing costs and, as it introduces a potential failure path, also lowers the reliability of the mobile telephone.
An object of the present invention is to provide an improved portable electronic device in which the use of a separate hardware switch to switch on and off the processor is unnecessary.
An object of the present invention is to simplify the manufacturing of portable electronic devices and to reduce their manufacturing costs.
Another object of the present invention is to improve the reliability of such devices.
The objects of the present invention are achieved by means of a portable electronic device in which the use of a separate hardware switch for switching on and off the device is unnecessary.
The portable electronic device in accordance with the present invention can be switched on by opening out the flip. This causes the flip position indicating switch to connect the processor to its power supply. When the processor is running it can keep the power supply connected by software means. With the flip open a first set of functions on the touch screen can be accessed by the user. The flip can be closed to access a second set of user functions. The action of closing the flip does not disconnect the processor from its power supply. One of the functions in the second set of user functions is an xe2x80x9coffxe2x80x9d function which is assigned to one of the keys of the keyboard. Activating this key causes the touch screen to register that the key has been pushed and causes the software to disconnect the processor from its power supply thereby shutting down the processor and removing it as a potential source of power leakage.
The invention will be explained in more detail by means of example of embodiments and with reference to the accompanying drawings.